Single anode rectifier with forced draft air cooling



c. CAUSSIN 2,905,851

SINGLE ANODE RECTIFIER WITH FORCED DRAFT AIR COOLING Sept. 22, 1959 Filed 001;. 9, 1957 Fig.

linv

Fig. 4

Fig.2

United States Patent Application October 9,1957, Serial No.. 689,064

7 Claims. (Cl. 313-163) The present invention relates to single anode rectifiers utilizing forced draft air cooling.

Single anode rectificrs produce a substantial amount of heat in the region of the cathode, which heat has to be removed in some manner. It has previously been suggested to cool these rectifiers by means of circulating water. However, it is not always possible to have sufficient water for cooling the rectifiers adequately, and it was therefore further suggested to utilize water refrigeration in a closed circuit combined with a water-air heat exchanger which comprises a radiator and a blower.

Certain designs contemplated an apparatus provided with additional vanes which increased the surface of the chamber into which the cooling air was directly blown. However, it was determined that the maximum temperature of the rectifier wall was between 45' to 55 C. and substantial difficulties arose in removing the heat from the hot region, when the ambient temperature reached 35 to 40 C.

Because of the above-mentioned difliculties, the rectifiers had to be modified to utilize an operating voltage of lower value, so that the rectifier could be cooled by water cooling alone.

In mercury vapor rectifiers large amounts of heat are developed at the cathode in comparison with other portions of the rectifier. However, a relatively high tempera ture zone must be maintained in some portions of the rectifier, such as near the anode, so as to prevent condensation of the mercury vapor. With water or air cooling it is not possible to produce zones of substantially different temperatures in the rectifier; The previously suggested solution of this problem was to introduce into the rectifier a thermal screen around and above the anode, which was rather inconvenient and did not satisfactorily control the temperature difference between the anode and the cathode.

In the present invention, 1 provide a single anode rectifier comprising a cooling system with forced draft air cooling which will eliminate the above-mentioned disadvantages, so that the cathode region is cooled to a greater extent than the anode region in the upper part of the rectifier. My invention allows the rectifier to be operated at its normal operating voltage without voltage increases to compensate for any modifications made accordingly to my invention.

According to the present invention the rectifier comprises an envelope which is water tight and encloses a mercury pool cathode in the inside part of the rectifier, and an anode disposed in the upper part of the rectifier. The water tight envelope is disposed in an enclosure which extends around at least the lower part of the rectifier, thereby forming a cavity between the envelope and the-enclosure. This cavity may be partially filled by a vaporizable liquid, the level of which is approximately the same as that of the mercury of the cathode. Means are also provided for cooling the vapors of said liquid by air under forced draft.

ice

Therefore, it is, an object of my invention to provide an improved single anode, rectifier. i

It is another object to provide an improved mercury vapor single anode rectifier.

It is a further object to, provide an improved ignijtron,

It is, an additional object to provide an improved single anode rectifier having a. mercury pool cathode, which rectifier is surrounded by an enclosure forming a cavity between the enclosure and the rectifier, which cavity is partially filled with a vaporizable liquid to a level at least as high as that of the mercury in the. mercury pool cathode.

It is an auxiliary object to provide an improved single anode rectifier having a mercury pool cathode, which rectifier is surrounded by an enclosure forming a cavity between the enclosure and the rectifier, which cavity is partially filled with a vaporizable liquid and having arrow 8 under forced draft.

the outer portion of the enclosure forcibly air cooled.

It is, a supplementary object to provide an improved single anode rectifier surrounded by an enclosure thereby forming a cavity between the enclosure and the rectifier, which cavity is partially filled by a vaporizable liquid, and which cavity is connected to a radiator the outside of which is cooled by forced air.

It is still another object to provide an improved rectifying device in which a plurality of single anode rectifiers are enclosed within an enclosure. thereby forming a cavity in; which the plurality of rectifiers are located, which cavity is partially filled with a vaporizable liquid andwhich cavity is connected to a radiator the outside of which is cooled by forced air.

These and other objects. of my invention will be apparent from the, following description, taken in accordance with the accompanying drawing, through which like reference characters indicate like parts, which drawing forms a part of this application and in which:

Figure l is a front sectional view of a single anode rectifier in accordance with one embodiment of my invention;

Fig. 2- is a top sectional view along the line II--Il of Fig. 1;

Fig. 3 is a front sectional view of a single anode rectifier in accordance with another embodiment of my invention; and i Fig. 4 is a schematically represented front sectional view of another embodiment of myinyention,

In Fig. 1 there is shown a single anode rectifier of the type known as an ignitron having a water tight envelope 1 containing the anode 2, which may be made of a material such as graphite, and a pool cathode 3 of a material such as mercury. A grid electrode 4 and an ignitor 27 are also shown. The lead 5 of the anode 2, may be insulated from the body of the rectifier by means of a tube 6 of insulating material such as glass, which is scaled into the envelope, or other suitable means, The envelope 1 is positioned in an enclosure 7 which is also water tight and which extends around the envelope 1 thereby forming a cavity 30 between the enclosure 7 and the envelope 1. A portion of the enclosure 7 surrounds the bottom of the device where the cathode 3 is positioned. In the embodiment shown in Fig. l the enclosure 7 also extends to the upper part of said envelope 1.v

As can be observed, particularly in Fig. 2, the upper part of the outer wall 2.8v of the enclosure is provided with a plurality of vane members 29 which may be cooled by air which is circulated in the direction ofthe In order to improve the cooling-action, the enclosure 7 is placed inside of a housing 9 forguiding the forcibly circulated air. An annular partition 10 is located inside of the enclosure 7 and has a passage 11 at its lower end and a passage 12 at its upper end. Preferably, the portion of the outer side of the enclosure 7 constituting vanes 29 does not reach to the bottom of the rectifier so that said lower part is enclosed by a cylindrical portion 13 only.

The enclosure 7 contains a coolant liquid 14 in sufiicient quantity to reach a level 15 which is at least as high as the level of the mercury in the cathode 3. The coolant liquid 14 may be water if desired. However, since the enclosure 7 must be under vacuum, other more volatile liquid materials may be more suitable, such as trichlorotrifluoroethane, better known commercially under the name of Freon-113. This liquid boils at about 45 C. under normal atmospheric pressure. It is chemically unreactive and is a good electric insulator. It is also possible to use other similar products, such as fluorides which preferably should not contain any hydrogen. Generally, any liquid can be used which is conventionally used in the refrigeration art.

When constructing the apparatus, the coolant liquid 14 can be poured in at atmospheric pressure by means of a small tube 16, located at the upper part of the enclosure 7. When the enclosure 7 is filled up with the coolant liquid 14 up to the level 15, it is heated to about 45 C. at which temperature the coolant liquid 14, if it is Freon, starts to boil. Its vapors replace the air in the enclosure and the tube 16 may then be sealed by a method such as welding.

The operation of my invention may be described as follows:

During the operation of the rectifier, the temperature of the cathode 3 increases, and the coolant liquid 14 which is disposed in the vicinity of the cathode 3 forms a substantial volume of gas by vaporization. This warm vapor rises along the wall 1 of the rectifier, and keeps the upper region of the rectifier at a temperature which is high enough to prevent any condensation of mercury vapor in this upper region of the rectifier.

The coolant vapor then passes through the passage 12 and comes into contact with the outer wall 28 of the enclosure 7. As the outer wall 28 is cooled by a forced air draft, the coolant vapor condenses to its liquid state upon striking it. The condensed liquid flows down the outer wall 28 until it reaches the base of the vanes, and then circulates through the passage 11 thereby reaching its starting point in the portion of the cavity 30 near the cathode 3.

Therefore, the rectifier is strongly cooled in the zone of the cathode 3 and is cooled to a lesser extent in the zone of the anode 2. This is particularly favorable for the operation of the rectifier. It is also possible to control the conditions of the operation by simply adjusting the level 15 of the liquid, i.e. controlling the amount of liquid vaporized in the enclosure.

Fig. 3 shows another embodiment of the present invention, comprising a water tight envelope 1 enclosing a mercury pool cathode 3, and an anode 2 located in the upper portion of the rectifier. The envelope 1 is surrounded by a water tight enclosure 17 thereby forming a cavity 31 which is partly filled with a coolant liquid 14 up to the level 18. The vapor from the coolant 14 travels in the direction of the arrow 19 into a radiator 20, which is cooled by forced draft of air. The coolant vapor condenses in the radiator 20 and flows down into the cavity 31 through a channel 21.

Finally, Fig. 4 shows another embodiment of the present invention. This embodiment comprises several rectifier tubes 22, which are disposed in a single housing 29, thereby forming a cavity 23 which contains a coolant liquid similar to that used in Figs. 1-3 up to a level 24. The cavity 23 is connected to a radiator (not shown) similar to that shown in Fig. 3 by an upper channel 25 for the vapor from the cavity 23 and by a lower channel 26 through which the condensed coolant returns by gravity into the rectifier. As in Figs. 1 to 3, the radiator is cooled by a forced draft of air.

. While the present invention has been shown in a few forms only, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modifications without departing from the spirit and scope thereof.

I claim as my invention:

1. In a single anode rectifier, the combination of an envelope enclosing a mercury pool cathode, an ignitor electrode and an anode, an enclosure enclosing said envelope, thereby forming a cavity between said enclosure and said envelope, said cavity being only partially filled with a vaporizable liquid to a level at least as high as that of the mercury in the mercury pool cathode.

2. In a single anode rectifier, the combination of an envelope enclosing a mercury pool cathode, an agnitor electrode and an anode, an enclosure enclosing said envelope, thereby forming a cavity between said enclosure and said envelope, said cavity being only partially filled with a vaporizable liquid to a level at least as high as that of the mercury in the mercury pool cathode, the outer portion of said enclosure located in the region of said anode being subject to forced air cooling.

3. In a single anode rectifier, the combination of an envelope enclosing a mercury pool cathode, an ignitor electrode and an anode, an enclosure enclosing said envelope, thereby forming a cavity between said enclosure and said envelope, said cavity being only partially filled with a vaporizable liquid to a level at least as high as that of the mercury in the mercury pool cathode, the outer portion of said enclosure located in the region of said anode comprising a plurality of vane members.

4. In a single anode rectifier, the combination of an envelope enclosing a mercury pool cathode, an ignitor electrode and an anode, an enclosure enclosing said envelope, thereby forming a cavity between said enclosure and said envelope, said cavity being only partially filled with a vaporizable liquid to a level at least as high as that of the mercury in the mercury pool cathode, the outer portion of said enclosure located in the region of said anode comprising a plurality of vane members, said vane members being subject to forced draft air cooling.

5. In a single anode rectifier, the combination of an envelope enclosing a mercury pool cathode, an ignitor electrode and an anode, an enclosure enclosing said envelope, thereby forming a cavity between said enclosure and said envelope, said cavity being only partially filled with a vaporizable liquid to a level at least as high as that of the mercury in the mercury pool cathode, and a housing member surrounding said enclosure.

6. In a single anode rectifier, the combination of an envelope enclosing a mercury pool cathode, an ignitor electrode and an anode, an enclosure enclosing said envelope, thereby forming a cavity between said enclosure and said envelope, said cavity being only partially filled with a vaporizable liquid to a level at least as high as that of the mercury in the mercury pool cathode, said cavity being connected to a radiator, the outside of which is exposed to forced draft air cooling.

7. In a rectifying device, the combination of a plurality of mercury pool cathode ignitrons within a single housing member, said housing member forming a cavity in which said ignitrons are positioned, said cavity being only partially filled with a vaporizable liquid to a level at least as high as that of the mercury in said ignitrons, said cavity being connected to a radiator, the outside of which is exposed to forced draft air cooling.

References Cited in the file of this patent UNITED STATES PATENTS 1,159,884 Aspinwall Nov. 9, 1915 1,159,910 Eaton et al. Nov. 9, 1915 2,016,885 Braband Oct. 8, 1935 2,135,883 Dallenbach Nov. 8, 1938 2,170,482 Mulder Aug. 22, 1939' 2,2427% Kingdon et al -4- May 20, 1941 

